package com.seeyoui.kensite.common.util;
/**
 * 坐标转换程序
 * 
 *  WGS84坐标系：即地球坐标系，国际上通用的坐标系。Earth

	GCJ02坐标系：即火星坐标系，WGS84坐标系经加密后的坐标系。Mars

	BD09坐标系：即百度坐标系，GCJ02坐标系经加密后的坐标系。  Bd09

	搜狗坐标系、图吧坐标系等，估计也是在GCJ02基础上加密而成的。
 * 	
 * 百度地图API		百度坐标
   腾讯搜搜地图API	火星坐标
   搜狐搜狗地图API	搜狗坐标*
   阿里云地图API	   火星坐标
   图吧MapBar地图API	图吧坐标
   高德MapABC地图API	火星坐标
   灵图51ditu地图API	火星坐标
 * 
 * @author fankun
 *
 */
public class CoordinateConvertUtil {
	private static  double PI 		= Math.PI;  
	private static  double AXIS 	= 6378245.0;  //
   private static  double OFFSET 	= 0.00669342162296594323;  //(a^2 - b^2) / a^2
   private static  double X_PI		= PI * 3000.0 / 180.0;

	//GCJ-02=>BD09 火星坐标系=>百度坐标系
	public static double[] gcj2BD09(double glat, double glon){
		double x = glon;
		double y = glat;  
		double[] latlon = new double[2];
	    double z = Math.sqrt(x * x + y * y) + 0.00002 * Math.sin(y * X_PI);  
	    double theta = Math.atan2(y, x) + 0.000003 * Math.cos(x * X_PI);  
	    latlon[0] = z * Math.sin(theta) + 0.006;
	    latlon[1] = z * Math.cos(theta) + 0.0065;  
	    return latlon;
	}
	
	//BD09=>GCJ-02 百度坐标系=>火星坐标系
	public static double[] bd092GCJ(double glat, double glon){
		double x = glon - 0.0065;
		double y = glat - 0.006;  
		double[] latlon = new double[2];
		double z = Math.sqrt(x * x + y * y) - 0.00002 * Math.sin(y * X_PI);  
		double theta = Math.atan2(y, x) - 0.000003 * Math.cos(x * X_PI);  
	    latlon[0] = z * Math.sin(theta);
	    latlon[1] = z * Math.cos(theta);  
	    return latlon;
	}
	//BD09=>WGS84 百度坐标系=>地球坐标系
		public static double[] bd092WGS(double glat, double glon){
			double[] latlon = bd092GCJ(glat,glon);
		    return gcj2WGS(latlon[0],latlon[1]);
		}
		// WGS84=》BD09   地球坐标系=>百度坐标系
	    public static double[] wgs2BD09(double wgLat, double wgLon) {  
	    	double[] latlon = wgs2GCJ(wgLat,wgLon);
		    return gcj2BD09(latlon[0],latlon[1]);
	    }  
	
	// WGS84=》GCJ02   地球坐标系=>火星坐标系
    public static double[] wgs2GCJ(double wgLat, double wgLon) {  
    	double[] latlon  = new double[2];
        if (outOfChina(wgLat, wgLon)){ 
        	latlon[0] = wgLat;  
        	latlon[1] = wgLon;  
           return latlon;  
         }  
        double[] deltaD =  delta(wgLat,wgLon);
        latlon[0] = wgLat + deltaD[0];
        latlon[1] = wgLon + deltaD[1];
	    return latlon;
    }  
    //GCJ02=>WGS84   火星坐标系=>地球坐标系(粗略)
    public static double[] gcj2WGS(double glat,double glon){
    	double[] latlon  = new double[2];
        if (outOfChina(glat, glon)){ 
        	latlon[0] = glat;  
        	latlon[1] = glon;  
           return latlon;  
         }  
        double[] deltaD =  delta(glat,glon);
        latlon[0] = glat - deltaD[0];
        latlon[1] = glon - deltaD[1];
	    return latlon;
    }
   //GCJ02=>WGS84   火星坐标系=>地球坐标系（精确）
    public static double[] gcj2WGSExactly(double gcjLat,double gcjLon){
    	 double initDelta = 0.01;
    	 double threshold = 0.000000001;
    	 double dLat = initDelta, dLon = initDelta;
    	 double mLat = gcjLat - dLat, mLon = gcjLon - dLon;
    	 double pLat = gcjLat + dLat, pLon = gcjLon + dLon;
    	 double wgsLat, wgsLon, i = 0;
         while (true) {
             wgsLat = (mLat + pLat) / 2;
             wgsLon = (mLon + pLon) / 2;
             double[] tmp = wgs2GCJ(wgsLat, wgsLon);
             dLat = tmp[0] - gcjLat;
             dLon = tmp[1] - gcjLon;
             if ((Math.abs(dLat) < threshold) && (Math.abs(dLon) < threshold))
                 break;
  
             if (dLat > 0) pLat = wgsLat; else mLat = wgsLat;
             if (dLon > 0) pLon = wgsLon; else mLon = wgsLon;
  
             if (++i > 10000) break;
         }
         double[] latlon = new double[2];
         latlon[0] = wgsLat;
         latlon[1] = wgsLon;
         return latlon;
    }
    
    //两点距离
    public static double distance(double latA, double logA, double latB,double  logB){
        int earthR = 6371000;
        double x = Math.cos(latA*Math.PI/180) * Math.cos(latB*Math.PI/180) * Math.cos((logA-logB)*Math.PI/180);
        double y = Math.sin(latA*Math.PI/180) * Math.sin(latB*Math.PI/180);
        double s = x + y;
        if (s > 1)
            s = 1;
        if (s < -1)
            s = -1;
        double alpha = Math.acos(s);
        double distance = alpha * earthR;
        return distance;
    }
     
    public static double[] delta(double wgLat, double wgLon){
    	 double[] latlng  = new double[2];
    	 double dLat = transformLat(wgLon - 105.0, wgLat - 35.0);  
         double dLon = transformLon(wgLon - 105.0, wgLat - 35.0);  
         double radLat = wgLat / 180.0 * PI;  
         double magic = Math.sin(radLat);  
         magic = 1 - OFFSET * magic * magic;  
         double sqrtMagic = Math.sqrt(magic);  
         dLat = (dLat * 180.0) / ((AXIS * (1 - OFFSET)) / (magic * sqrtMagic) * PI);  
         dLon = (dLon * 180.0) / (AXIS / sqrtMagic * Math.cos(radLat) * PI);  
         latlng[0] =dLat;
         latlng[1] =dLon;
  	      return latlng;
    }
    
    public static boolean outOfChina(double lat, double lon){  
        if (lon < 72.004 || lon > 137.8347)  
            return true;  
        if (lat < 0.8293 || lat > 55.8271)  
            return true;  
        return false;  
    }  

    public static double transformLat(double x, double y){  
        double ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * Math.sqrt(Math.abs(x));  
        ret += (20.0 * Math.sin(6.0 * x * PI) + 20.0 * Math.sin(2.0 * x * PI)) * 2.0 / 3.0;  
        ret += (20.0 * Math.sin(y * PI) + 40.0 * Math.sin(y / 3.0 * PI)) * 2.0 / 3.0;  
        ret += (160.0 * Math.sin(y / 12.0 * PI) + 320 * Math.sin(y * PI / 30.0)) * 2.0 / 3.0;  
        return ret;  
    }  

    public static double transformLon(double x, double y){  
        double ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.sqrt(Math.abs(x));  
        ret += (20.0 * Math.sin(6.0 * x * PI) + 20.0 * Math.sin(2.0 * x * PI)) * 2.0 / 3.0;  
        ret += (20.0 * Math.sin(x * PI) + 40.0 * Math.sin(x / 3.0 * PI)) * 2.0 / 3.0;  
        ret += (150.0 * Math.sin(x / 12.0 * PI) + 300.0 * Math.sin(x / 30.0 * PI)) * 2.0 / 3.0;  
        return ret;  
    }  
}
